Safety cabinet switch



Feb. 5, 1952 A LAUDER 2,584,390

SAFETY CABINET SWITCH Filed July 14, 1950 INVENTOR; Wm/ace A. Lauder A T TORNE Y5,/

Patented Feb. 5, 1952 SAFETY CABINET SWITCH Wallace A. Lauder, West Nyack, N. Y., assignor, by mesne assignments, to Reconstruction Finance Corporation, New York, N. Y., a corporation of the United States Application July 14, 1950, Serial No. 173,919

Claims.

This invention relates to safety switches, and has for one of its objects to provide a switch designed for use with cabinet enclosed, high power electrical equipment, wherein safety for a service man is assured by automatically cutting off the current to the enclosed mechanism whenever the cabinet door is opened.

It is a primary object to provide switch mechanism of this kind which includes a manually operable actuator adapted to be set and maintained in a position to close the switch while the door is open so that a test can be made, but to be automatically disabled so that the switch will be returned to automatic door control in response to closing of the door. This action eliminates the necessity of tying down a conventional switch by putting a jumper across the terminals for testing. The jumper, if used, may be forgotten at the completion of the service operation, and later cause injury to a maintenance man who fails to notice the jumper.

In the drawings:

Fig. 1 is a top plan view of the switch in place on a cabinet wall;

Fig.2 is a front elevation taken along the line 2-2 of Fig. 1;

Fig. 3 is a side elevation taken on line 3--3 of Fig. 2; and

Fig. 4 is a fragmentary front elevation similar to Fig. 2, but illustrating the manual actuator in switch closing position.

In the drawings a switch, generally indicated atLis fastened on the side wall'2 of a cabinet or any other structure by means of bolts 3 which are passed through the rear section of the switch casing structure and into the side wall 2. The switch I is spaced from the side wall 2 by means of washers 4.

A door 5 of the cabinet is partially shown. The door when in its closed position (shown in dot and dash lines in Fig. 1) fits into a recessed portion 6 of the side wall 2 of the cabinet. The door 5 is adapted when closed to press against a leaf actuator or spring arm I to effect completion of a switch controlled circuit as explained hereinafter.

The actuator "I is fastened at one end upon switch casing 8 by rivets l3 and I4 so as to form a cantilever type spring.

The switch I comprises the casing 8 formed of A non-conducting material, from which extend metallic tongues or terminals 9, I 0 and II. The switch mechanism (not shown) is enclosed within the casing 8. This mechanism is of the snapaction typ and is fully disclosed in a. pending application of Peter J. McLaren and Cyril 0.

2 Benson, Serial No. 718,832, filed December 27.. 1946, now Patent No. 2,521,015, dated September 5, 1950, for Snap-Over Toggle Switch. The tongues 16 and Ii are connected in the power circuit of the equipment enclosed within the cabinet in the fashion explained in the copending application of McLaren et at. cited above.

The switch mechanism is actuated by a plunger [2, best shown in the side elevation view (Fig. 3), which is biased outwardly, that is, in a direction to cause it to project from the casing 8. When the plunger [2 is in its outward position the current circuit is broken, the reverse being true when it is in its inward position. The plunger I2 is actuated toward its inward position by the leaf actuator or spring arm 1. Thus, when the door 5, in its closed position, bears against the free end of the leaf actuator l, the plunger 12 is forced into the casing 8 to close the circuit of the power equipment inside the cabinet. This is the normal condition of the parts.

When the door is opened, the leaf actuator l springs away from the casing 8, allowing the plunger to move outward. The outward movement of the plunger, in turn, permits the switch mechanism automatically to move to an open circuiting condition.

The switch casing 8 contains at its lower portion a pair of upstanding bored ears [5 and 16 which slidingly support a rod actuator IT.

The rod actuator constitutes a manually operable means for shifting the leaf actuator to, and detaining it in, circuit closing position while the door 5 is open, and for automatically restoring the leaf actuator to automatic door control upon the closing of the door.

The rod actuator I"! is provided with a stop portion I8 at one end and is surrounded at the other end by a compression coil spring I9. The spring I9 is disposed between ear I5 of the easing and the head 20 of the rod actuator I1. The spring l9 biases the rod actuator ll towards the right as viewed in Fig. 2. The rod actuator I! has two grooves, 21 and 22 formed in it, which cooperate with an upstanding projection or rib 23 of the leaf actuator or spring arm I.

The normal position of the rod actuator is the position shown in Fig. 2. When the door is opened the leaf actuator ll, under its own bias, raises the rib 23 into the groove 2| of the rod actuator. Under these conditions the circuit to the power equipment is broken, and the power equipment within the cabinet is cold and can be freely worked upon.

When it is desired manually to close the switch 3 while keeping the door open, the rod actuator I7 is moved by hand into the position shown in Fig. 4. As the groove 2! is moved away from registry with the rib 23, the rib rides onto the full dia.. eter portion of the rod and is cammed by the rod to switch closing position. In the position of Figure la shallow groove 22 has been moved into register with the rib The groove 22 is not deep enough to permit the switch to open, but it does cooperate with the rib 23 to detain the rod actuator in the Fig. 4 position. This means of course, that the rod actuator is yieldingly detained in switch closing position.

When the leaf actuator 1' is moved fully to the left, however, as shown in Fig. 3, by the closing of the cabinet door 5, the embossed rib 23 is shifted out of engagement with the groove 22, thus freeing the rod actuator H. The spring ls, therefore. restores the rod H to its normal position as shown in Fig. 2 with the deepest part of groove 2! in register with the rib It will now be apparent that the structure herewith presented may be used as asaiety device in. conjunction with cabinet structure or any other structure in which high voltage electric or electronic equipment is maintained, and that upon opening of the cabinet door the circuit of the power equipment contained therein will be automatically broken. If, however, the person opening the door wishes to test or repair the equipment contained therein, he merely pushes the rod actuator ii as shown in Fig. 2 to the left so that the rib 23 engages the groove 22 as shown in Fig. l. The circuit to the power e ipment in the cabinet is thus completed and maintained as long as desired. Upon completion of the in spection or repair, the service man merely closes the cabinet door. This automatically restores the switch to automatic door control.

I have described what I believe to be the best embodiments of my inv ntion. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a safety cut-out switch for high power electric equipment, a switch actuating plunger, a spring arm including a standing rib, a rod actuator including two cut-out portions, said rod actuator being biased to a normal position and adapted to be held in a second position by interaction between one of its cut-out surfaces and said upstanding rib, said rod actuator adapted to be released by depression of the spring arm.

2. In apparatus of the class described, a switch actuating plunger biased to an extended position; a spring arm adapted to contact said switch actuating plunger including a ribbed portion, a rod actuator including two cut-out portions, said rod actuator biased so that said rib portion normally extends into one of said cut-out portions, said ribbed portion adapted to engage the other of said cut-out portions to hold the switch actuating plunger against its bias.

3. In an interlock switch apparatus mounted on the inside of a cabinet, a switch actuating plunger biased into an extended circuit breaking position, a spring arm contacting said plunger, a rib on said spring arm, said spring arm adapted to be engaged by the door of said cabinet in its closed position; a rod actuator mounted for movement perpendicular to said spring arm, said rod actuator including two cut-out portions, the first of said c 't-out portions being of suihoient depth to allow free n'iovement of said spring arm, the second of said cut-out portions being shallow to engage said rib on said spring arm.

4. In apparatus of the class described, a switch actuating plunger, a leaf actuator including a rib, a spring biased rod mounted for slidable movement normal to said leaf actuator and including two cut-out portions, the first deep enough to clear the leaf actuator when said actuator is in the open-sir ch position, and the second comparatively shallow to interfit with the rib and maintaining the switch in closed position.

5. In apparatus of the class described, a switch casing, a switch actuating plunger extending through said casing, a spring arm attached to casing at one end and extending across said plunger, 2. projecting rib on said spring arm, a rod actuator mounted for slidable movement above said spring arm including two cut-out portions, one cut-out portion adapted to be cleared by said rib, the other adapted to be engaged by said rib.

WALLACE A. LAUDER.

REFERENCES CITED UNITED STATES PATENTS Name Date Jacobs May 1'7, 1949 Number 

